Predicted cumulative stellar mass density evolution (SMD) in stars, ρ_★, and globular clusters, ρ_★(GC), as a function of redshift. The SMDs are derived from the star formation and globular cluster formation rate densities, ρ_SFR and ρ_GC, respectively, shown in Fig. 1. The shaded area indicates the range between (1 − 4) times the observed cosmic stellar mass density in GCs derived at z ∼ 0 by Harris et al. (2013), to account for the higher initial masses of GCs.